During operation of a spark ignited engine equipped with an exhaust gas recirculation system, the combustion cylinders are provided with a “charge” consisting of fuel, air and recirculated exhaust. This charge is ignited within the cylinders by the igniter of the engine's ignition system.
The amount of energy needed for a given ignition system to initiate and sustain combustion throughout the cylinder is dependent on variables such as temperature, pressure, flow velocities and composition of the charge. These variables make the ignition system a cause of combustion instabilities.
Conventionally, combustion instability is addressed by increasing the energy or power of the ignition system. However, conventional spark ignition systems, which include both capacitive and inductive discharge electrical systems and chemical pilot ignition systems, are limited in the amount of energy they can deliver to chamber through the ignitor.